package com.personal.o2o.dao.split;

import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.keygen.SelectKeyGenerator;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.transaction.support.TransactionSynchronizationManager;

import java.util.Locale;
import java.util.Properties;

@Intercepts({@Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class}),
        @Signature(type = Executor.class, method = "query", args = {MappedStatement.class,
                                                                    Object.class,
                                                                    RowBounds.class,
                                                                    ResultHandler.class})})
public class DynamicDataSourceInterceptor implements Interceptor {
    private static Logger logger = LoggerFactory.getLogger(DynamicDataSourceInterceptor.class);

    private static final String REGEX = ".*insert\\u0020.*|.*delete\\u0020.*|.*update\\u0020.*";

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        boolean synchronizationActive = TransactionSynchronizationManager.isSynchronizationActive();
        Object[] objects = invocation.getArgs();
        MappedStatement ms = (MappedStatement) objects[0];
        String lookupkey = DynamicDataSourceHolder.DB_MASTER;;
        // 如果不是用事务管理起来的
        if (synchronizationActive != true) {
            //读方法
            if (ms.getSqlCommandType().equals(SqlCommandType.SELECT)) {
                // selectKey 为自增id查询主键(SELECT LAST_INSERT_ID())方法，使用主库
                if(ms.getId().contains(SelectKeyGenerator.SELECT_KEY_SUFFIX)) {
                    lookupkey = DynamicDataSourceHolder.DB_MASTER;
                }else {
                    BoundSql boundSql = ms.getSqlSource().getBoundSql(objects[1]);
                    String sql = boundSql.getSql().toLowerCase(Locale.CHINA).replaceAll("[\\t\\n\\r]", "");
                    if (sql.matches(REGEX)) {
                        lookupkey = DynamicDataSourceHolder.DB_MASTER;
                    }else {
                        lookupkey = DynamicDataSourceHolder.DB_SLAVE;
                    }
                }
            }
        }else{
            lookupkey = DynamicDataSourceHolder.DB_MASTER;
        }
        logger.debug("设置方法[{}] use [{}] Strategy,SqlCommanType [{}]..", ms.getId(),lookupkey,ms.getSqlCommandType().name());
        DynamicDataSourceHolder.setDbType(lookupkey);
        return invocation.proceed();
    }

    @Override
    public Object plugin(Object target) {
        // 如果目标连接是这个ibitis,
        if (target instanceof Executor) {
            return Plugin.wrap(target,this);
        }else{
            return target;
        }
    }

    @Override
    public void setProperties(Properties properties) {

    }
}
